|Date: September 30, 2004||HC# 060142-265|
Re: Combined Effects of Echinacea, Propolis, and Vitamin C in Preventing Upper Respiratory Infections in Children
Cohen H, Varsano I, Kahan E, Sarrell M. Effectiveness of an herbal preparation containing echinacea, propolis, and vitamin C in preventing respiratory tract infections in children. Archives of Pediatric and Adolescent Medicine. 2004;158:217-221.
Since the passage of the Dietary Supplements Health and Education Act in 1994, consumer sales of herbal products have increased by approximately 10-15% per year. Echinacea (Echinacea purpurea, E. pallida, and E angustifolia) is one of the most popular herbal medicines in Europe and the United States and is used primarily for the prevention and treatment of upper respiratory tract illnesses. The immune-stimulating activity of echinacea has been demonstrated in animal and in vitro studies. Propolis, a resinous substance collected from various plant sources by honeybees, also has a history of use for the management of respiratory tract infections. Studies have shown propolis to have antiviral and anti-inflammatory activities. Vitamin C (ascorbic acid) has been reported to have an immune-stimulating effect, and high doses are touted to prevent and treat the symptoms of the common cold. Despite the widespread use of these substances, few clinical trials of their safety and efficacy have been conducted in humans, particularly children. The objective of this study was to evaluate the safety and efficacy of a preparation containing echinacea extract, propolis, and vitamin C in preventing upper respiratory tract infections in children.
A randomized, double-blind, placebo-controlled study was conducted in children aged 1-5 years during the wintertime. The children were randomly assigned to receive either placebo or a preparation (Chizukit™; Hadas Corp. Ltd., Yokneam, Israel) containing 50 mg/mL echinacea (upper portion of E. purpurea and roots of E. angustifolia), 50 mg/mL propolis, and 10 mg/mL of vitamin C twice daily at a dosage of 5.0 mL for children aged 1-3 years and 7.5 mL for children aged 4-5 years, with increases during respiratory illness episodes. Follow-up visits were made at 4, 8, and 12 weeks, at which time data on compliance, respiratory tract morbidity, and adverse drug reactions were collected. The primary outcomes included the total number and duration of episodes of respiratory tract infections and the total number of illness days. The secondary outcomes included the number of days with fever, cough, and cold and the duration of antipyretic or antibiotic use.
Three hundred twenty-eight children completed the study, 160 in the Chizukit group and 168 in the placebo group. The total number of episodes of an infection and the total number of illness days were, respectively, 55 and 59% lower in the Chizukit group (significance level not stated). The number of children who experienced at least one upper respiratory tract infection, the mean number of episodes per child, the days of illness per child, and the duration of individual episodes were all significantly lower (P < 0.001) in the Chizukit group than in the placebo group (by 43%, 55%, 50%, 58%, and 45%, respectively). The number of days with fever, the number of days of antipyretic use, the number of days of antibiotic use, the number of physician visits for a respiratory tract illness, and the number of days absent from school or day care were all significantly (P < 0.001) lower in the Chizukit group than in the placebo group (by 62%, 53%, 50%, 36%, and 49%, respectively). The number of adverse drug reactions was not significantly different (P = 0.54), in the Chizukit group compared to the placebo group; 9 and 7 patients, respectively, had mild gastrointestinal and palatability symptoms.
The results indicate that the echinacea extract, propolis, and vitamin C preparation tested "has a significant beneficial effect on the incidence and severity of respiratory tract infections in young children." The authors assume that this beneficial effect resulted from the immunomodulatory action of Echinacea and propolis. The authors note, however, that this study was limited by its lack of quality control and standardization because the active ingredients of the product are unknown. Furthermore, some researchers have suggested that the immune-stimulating properties of echinacea decline with continued use and therefore recommend that echinacea-containing products not be taken for more than 8-12 consecutive weeks. Additional studies in larger populations and in specific populations at risk of upper respiratory tract infections, such as allergic children, are needed before this preparation can be recommended routinely.
—Brenda Milot, ELS